Effects of Variation of Flow and Accumulation of Suspended Solids on the Performance of Anaerobic/Aerobic Biofilm System Applied to Grey Water Treatment

Abstract

Effects of daily variation of flow and accumulation of suspended solids on the performance of submerged anaerobic/aerobic biofilm systems were investigated by laboratory study using synthetic wastewater and by field study using grey water.
The concentration of dissolved organic carbon (DOC) in effluent from anaerobic filter did not change corresponding to the change in flow both in laboratory and in field study when daily average hydraulic retention time in anaerobic filter (HRTa) was 20 h. In field study, however, percent removal of DOC by anaerobic filter was considerably smaller (20-30%) than that of laboratory study (90-95%) at HRTa of 20 h. The low percent removal of DOC by anaerobic filter was caused firstly by organic release from suspended solids accumulated in the anaerobic filter and secondly by channering flow with the accumulation of the suspended solids. Nitrogen release from suspended solids was also observed in anaerobic filter